GDF15 and familial pancreatic carcinoma: The biliary MIC-1 level was found to be equivalent in biliary cancer and pancreatic cancer [678 (0–6383) pg/ml vs. 1031 (0–5937) pg/ml, P = 0.99] according to the Mann-Whitney U test, and the serum MIC-1 levels were also found to be equivalent (3860 ± 2271 pg/ml vs. 3272 ± 1438 pg/ml, P = 0.36) according to Student’s t test.